Construction of Low‐Coordination Cu−C₂ Single‐Atoms Electrocatalyst Facilitating the Efficient Electrochemical CO₂ Reduction to Methane

Abstract

Abstract Constructing Cu single‐atoms (SAs) catalysts is considered as one of the most effective strategies to enhance the performance of electrochemical reduction of CO 2 (e‐CO 2 RR) towards CH 4 , however there are challenges with activity, selectivity, and a cumbersome fabrication process. Herein, by virtue of the meta‐position structure of alkynyl in 1,3,5‐triethynylbenzene and the interaction between Cu and −C≡C−, a Cu SAs electrocatalyst (Cu−SAs/HGDY), containing low‐coordination Cu−C 2 active sites, was synthesized through a simple and efficient one‐step method. Notably, this represents the first achievement of preparing Cu SAs catalysts with Cu−C 2 coordination structure, which exhibited high CO 2 ‐to‐CH 4 selectivity (72.1 %) with a high CH 4 partial current density of 230.7 mA cm −2 , and a turnover frequency as high as 2756 h −1 , dramatically outperforming currently reported catalysts. Comprehensive experiments and calculations verified the low‐coordination Cu−C 2 structure not only endowed the Cu SAs center more positive electricity but also promoted the formation of H•, which contributed to the outstanding e‐CO 2 RR to CH 4 electrocatalytic performance of Cu−SAs/HGDY. Our work provides a novel H⋅‐transferring mechanism for e‐CO 2 RR to CH 4 and offers a protocol for the preparation of two‐coordinated Cu SAs catalysts.